Baltics Game

The Baltics Game was the nickname given to the competition between the Soviet Union and NATO over control of the Baltic Sea. Soviet Navy submarines regularly pushed boundaries and crossed lines, creating fears that the Soviets would invade Scandinavia. Soviet skirmishes with Finland and maritime incursions into the territorial waters of Sweden and Denmark threatened the fragile peace of the Cold War, and the result was an increased NATO naval presence in the Baltics.

History
The border changes that World War II had left behind in 1945 included the Soviet Union's annexation of Latvia, Lithuania, Estonia, and East Prussia (which became Kaliningrad Oblast), and Poland became a communist state and an ally of the USSR. In April 1949, the Western Allies (United States, United Kingdom, France, Italy, Belgium, and the Netherlands) formed NATO to counteract the USSR's growing sphere of influence (the "Eastern Bloc"), which included its puppet governments in Hungary, Poland, Czechoslovakia, Albania, Denmark, Norway and Yugoslavia. Sweden was traditionally a neutral country, having had neutrality since 1814, but NATO wanted to court Sweden in order to gain the support of a large country in Scandinavia against expanding Soviet influence in the Baltic Sea region. Sweden was a member of the Non-Aligned Movement, but it was not any more welcome to Soviet naval presence in its waters than any NATO country.

Skelleftea incident
On 20 January 1950, a Soviet submarine traveled towards the Swedish coast at Skelleftea, coming dangerously close to Swedish territorial waters. In response to this, several Swedish ships and submarines were deployed to prevent the Soviet submarine from encroaching into its territory. The situation nearly escalated into an armed confrontation, but the Soviet submarine later backed off, defusing the incident.